import java.util.Scanner;


class Test2 {
    public void func() {
        System.out.println("Test2::func()");
    }
}
public class Test {

    public static String func(String str) {
        boolean[] flg = new boolean[255];
        StringBuilder sb = new StringBuilder();
        for(int i = 0;i < str.length();i++) {
            char ch = str.charAt(i);
            if(flg[ch] == false) {
                sb.append(ch);
                flg[ch] = true;
            }
        }
        return sb.toString();
    }

    public void merge(int A[], int m, int B[], int n) {
        int i = m-1;
        int j = n-1;
        int k = m+n-1;
        while(i >= 0 && j >= 0) {
            if(A[i] <= B[j]) {
                A[k] = B[j];
                j--;
                k--;
            }else{
                A[k] = A[i];
                i--;
                k--;
            }
        }
        while(j >= 0) {
            A[k] = B[j];
            j--;
            k--;
        }

        while(i >= 0) {
            A[k] = A[i];
            i--;
            k--;
        }
    }

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        while(scan.hasNextLine()) {
            String str = scan.nextLine();
            String ret = func(str);
            System.out.println(ret);
        }
    }

    public static void main2(String[] args) {
        Test2 test2 = new Test2() {
            @Override
            public void func() {
                System.out.println("我是重写的func!!!");
            }
        };
        test2.func();
    }

    public static void main1(String[] args) {
        new Test2() {
            @Override
            public void func() {
                System.out.println("我是重写的func!!!");
            }
        }.func();
    }
}